Abstract

Background

Advances in ultrasound imaging technology have made it more accessible to prehospital
providers. Little is known about how ultrasound is being used in the prehospital environment
and we suspect that it is not widely used in North America at this time. We believe
that EMS system characteristics such as provider training, system size, population
served, and type of transport will be associated with use or non-use of ultrasound.
Our study objective was to describe the current use of prehospital ultrasound in North
America.

Methods

This study was a cross-sectional survey distributed to EMS directors on the National
Association of EMS Physicians (NAEMSP) mailing list. Respondents had the option to
complete a paper or electronic survey.

Results

Of the 755 deliverable surveys we received 255 responses from across Canada and the
United states for an overall response rate of 30%. Of respondents, 4.1% of EMS systems
(95% CI 1.9, 6.3) reported currently using ultrasound and an additional 21.7% (95%
CI 17, 26.4) are considering implementing ultrasound. EMS services using ultrasound
have a higher proportion of physicians (p < 0.001) as their highest trained prehospital
providers when compared to the survey group as a whole. The most commonly cited current
and projected applications are Focused Abdominal Sonography for Trauma (FAST) and
assessment of pulseless electrical activity (PEA) arrest. The cost of equipment and
training are the most significant barriers to implementation of ultrasound. Most medical
directors want evidence that prehospital ultrasound improves patient outcomes prior
to implementation.

Conclusions

Prehospital ultrasound is infrequently used in North America and there are a number
of barriers to its implementation, including costs of equipment and training and limited
evidence demonstrating improved outcomes. A research agenda for prehospital ultrasound
should focus on patient-important outcomes such as morbidity and mortality. Two commonly
used indications that could be a focus of standardized training programs are the FAST
exam, and assessment of PEA arrest.